/*
* Copyright (c) 2000, 2005, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.rmi.runtime;
import java.security.AccessController;
import java.security.PrivilegedAction;
import sun.security.util.SecurityConstants;
/**
* A PrivilegedAction for creating a new thread conveniently with an
* AccessController.doPrivileged construct.
*
* All constructors allow the choice of the Runnable for the new
* thread to execute, the name of the new thread (which will be
* prefixed with "RMI "), and whether or not it will be a daemon
* thread.
*
* The new thread may be created in the system thread group (the root
* of the thread group tree) or an internally created non-system
* thread group, as specified at construction of this class.
*
* The new thread will have the system class loader as its initial
* context class loader (that is, its context class loader will NOT be
* inherited from the current thread).
*
* @author Peter Jones
**/
public final class NewThreadAction implements PrivilegedAction<Thread> {
/** cached reference to the system (root) thread group */
static final ThreadGroup systemThreadGroup =
AccessController.doPrivileged(new PrivilegedAction<ThreadGroup>() {
public ThreadGroup run() {
ThreadGroup group = Thread.currentThread().getThreadGroup();
ThreadGroup parent;
while ((parent = group.getParent()) != null) {
group = parent;
}
return group;
}
});
/**
* special child of the system thread group for running tasks that
* may execute user code, so that the security policy for threads in
* the system thread group will not apply
*/
static final ThreadGroup userThreadGroup =
AccessController.doPrivileged(new PrivilegedAction<ThreadGroup>() {
public ThreadGroup run() {
return new ThreadGroup(systemThreadGroup, "RMI Runtime");
}
});
private final ThreadGroup group;
private final Runnable runnable;
private final String name;
private final boolean daemon;
NewThreadAction(ThreadGroup group, Runnable runnable,
String name, boolean daemon)
{
this.group = group;
this.runnable = runnable;
this.name = name;
this.daemon = daemon;
}
/**
* Creates an action that will create a new thread in the
* system thread group.
*
* @param runnable the Runnable for the new thread to execute
*
* @param name the name of the new thread
*
* @param daemon if true, new thread will be a daemon thread;
* if false, new thread will not be a daemon thread
*/
public NewThreadAction(Runnable runnable, String name, boolean daemon) {
this(systemThreadGroup, runnable, name, daemon);
}
/**
* Creates an action that will create a new thread.
*
* @param runnable the Runnable for the new thread to execute
*
* @param name the name of the new thread
*
* @param daemon if true, new thread will be a daemon thread;
* if false, new thread will not be a daemon thread
*
* @param user if true, thread will be created in a non-system
* thread group; if false, thread will be created in the system
* thread group
*/
public NewThreadAction(Runnable runnable, String name, boolean daemon,
boolean user)
{
this(user ? userThreadGroup : systemThreadGroup,
runnable, name, daemon);
}
public Thread run() {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION);
}
Thread t = new Thread(group, runnable, "RMI " + name);
t.setContextClassLoader(ClassLoader.getSystemClassLoader());
t.setDaemon(daemon);
return t;
}
}